<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Test16</title>
</head>
<body>
    <script type="text/javascript">
        var num = 1;
        for (var i = 1 ; i <=13 ; i++){
            num = num*i;
        }
        console.log("13的阶乘为" + num);
    </script>
</body>
</html>